Optix doesn't support some nodes like the 'Bevel' or the 'Ambient Occlusion' node. It doesn't matter if they are connected to the material output or not, but if they are even present in the shader editor window, the scene will no longer render. Try it out with a fresh scene.
Blego uses the Bevel node for its Edge Wear function, and hence doesn't work in Optix. Please use CUDA instead.
Sorry about this, it is a bummer, I know. But we just have to wait for the Blender devs to fix it.
Edge Wear is currently not supported by Eevee, everything else will work just fine.
If you are using Cycles, and still are facing a problem, then you need to download the latest 2.79 'Experimental' build from builder.blender.org/download/
Sorry for the inconvenience. I am sure this will be resolved with the next stable Blender release. Thanks for your support. :)
Download an experimental 2.8 build from builder.blender.org/download/
Yes, the one shown in the images. I prefer the term Blego Brick. :p
No, the shader uses 'object' texture coordinates, thus, you need not worry about UVs at all.
You need to apply scale.
Select model. Hit 'Ctrl+A'. Select 'Scale'.
Yes, Blego is compatible with both Cycles and Eevee rendering engines.
Yes, mostly. Everything except the fingerprints and scratches is procedural.